Mac Mini with a desk top iMac

My iMac (Mac OS X, version 10.6.8, Processor 3.06 GHz, Intel Core 2 Duo, Memory 4GB 1067 MHz DDR3) is too old for updates to run efficiently. I own a Mac Mini, (Mac OS X, version 10.7.5, Processor 2.5 GHz Intel Core i5, Memory 4 GB 1333 MHz DDR3). Can I use my older iMac desk top as a screen for Mac Mini? If this is possible, what accessories would I need to buy? Also, are there any step by step directions to follow to accomplish this task. Finally, would I still be able to use the cd/dvd hardware from my desk top once I connect the Mac Mini? Thank you for your time and efforts.